Questions about engine oil.

[ang@hamlet.ucs.indiana.edu]

Hi all,

I have a questions about the engine oil and hope anyone on the list could be 
kind to help. I used to using the Castrol 5w-50 engine oil for my 5kcst. 
Last week, I changed the engine oil to the Mobil 5w-30, after a 30 miles 
trip the oil pressure lite came on when the car restart. The weather now 
here in Bloomington, Indiana is around 25F to 45F and still no snow yet. 
Also, after I read the viscosity chart in owner's menu and I found that 
the 5w-30 engine oil's temperature range is only form -20F to 20F.  


I am not really familiar with the engine oil therefor my questions are: 

Am I using the wrong viscosity grade of engine oil?

It that bacause I'm using the 5w-30 oil so that it triggered the oil 
pressure lite?



   Thank you 
       &
Happy Thanksgiving

Albert Ng
87 5kcst